This invention relates liquid ring vacuum pumps in general and more particularly to an improved pump set comprising a liquid ring vacuum pump preceeded by a compressor.
Pump sets consisting of a liquid ring vacuum pump preceeded by a compressor, such as a Roots pump are well known in the art. Devices of this nature are used for suctioning and compressing media in gaseous or vapor form down to a vacuum of 100 Torr. Because displacement pumps such as Roots pumps are relatively complicated in design and require a large amount of maintenance, jet pumps have been used as precompressors in many applications. This is true even though this requires tolerating a larger liquid ring vacuum pump because it must also handle the operating fluid used in the injector pump.
Thus, neither of the methods of implementing such a pump set in the prior art are completely satisfactory. In view of this, it is the object of the present invention to provide an improved pump set of this nature which combines great ruggedness, reliability, small space requirements and has comparatively low power requirements with respect to the intake volumne.